Fielding Questions: Pineapple plant fruiting in ND, horseradish care, peat alternative

Q: I’d love to share some of the two pineapples I just harvested today in Mercer County, N.D, – Jessie Krieger.

A: When I hear of pineapple plants producing fruit, I visualize plantations in tropical Hawaii. And so, Jesse, you caught my immediate attention when you said you enjoyed homegrown pineapple in Scranton, N.D. I’ll let Jesse tell the tale.

“The photos are from August 2019 when I harvested my first pineapple fruit, which was about the size of a store-bought one. I started the plant from the top cut off a pineapple we purchased from the grocery store, and it took three years to grow the plant from start to finish.

“During the December before it fruited, I set a couple of ripening apples beside the pot and covered the very large plant loosely with plastic, which supposedly would trigger blossoming with the apple’s ethylene gas. It worked and by mid-January a spike with a tiny pineapple came up.

“The plant stayed in the house until May, and then went into my greenhouse. I fed it with Miracle Gro and by the end of of August, the fruit was fully ripe and very sweet.

“I then broke the top of the pineapple apart and rooted seven little pineapple plants from it. This set has taken the past four years to produce fruit, because the tops were so much smaller than the one I rooted the first time. All of this year’s fruit were a little smaller, but followed pretty much the same timeline – blooming in January after the apple ethylene gas treatment and ripening in the fall.

“The pineapple plants were repotted twice, going into a larger deck pot the last time. Each plant produces one fruit and several plant suckers at the base. “

Thanks, Jessie, for an inspirational story, and you’ve proven that pineapple tops can be rooted and brought to fruiting, even though the upper Midwest isn’t exactly the Hawaiian tropics.

Q: Is it okay to cut horseradish leaves down to a couple inches this time of year? They are getting pretty unsightly. – Todd B.

A: Horseradish leaves can be cut down in autumn to an inch or two above ground level, but wait until frost has killed the leaves, or the plants appear to be going dormant. The roots of horseradish make their greatest growth in late summer and early fall, and if the leaves look healthy, they continue to feed the roots.

If you’re planning to harvest the horseradish roots this year, delay digging until late October or early November. It can also be dug in early spring.

Q: I’ve been using peat-based potting soil for container gardening for over 30 years. Now I’m learning that peat moss is not a renewable resource, or at least in our lifetimes. What alternatives can you suggest? – Lisa P.

A: Peat has been a staple for most of our gardening lives, but because it takes over a thousand years to form about three feet of peat in a bog, we’ve been using it at a faster rate than it can possibly replenish.

Luckily there are good alternatives. For amending outdoor soil, compost and other organic materials work beautifully.

For potting soil and seed starting, coconut coir is a wonderful ingredient. It’s already being used in some national brand potting and seed-starting mixes. Compressed bricks of coconut coir can be ordered online and will probably become more readily available at garden centers.